Semiconductor device fabrication can include the bonding of two (or more) semiconductor wafers. For example, wafer bonding can be utilized in the fabrication, e.g., formation, process of infrared (IR) detectors and fluidic devices, among other types of semiconductor devices.
Semiconductor wafers can be bonded using, for example, a solder bonding process. A solder bonding process can include melting a filler metal, such as, for example, indium or a lead-indium alloy, between the wafers, and using the melted filler metal to bond, e.g., join, the wafers.
Such a soldered wafer bond, however, may not be able to withstand (e.g., may fail at) temperatures of approximately 200 degrees Celsius or greater. Further, a soldered wafer bond may include voids, and accordingly may not provide a hermetic, e.g., airtight, seal.
Semiconductor wafers can also be bonded using a solid-liquid interdiffusion (SLID) bonding process. A SLID bonding process can include forming high-temperature phases by diffusion in the presence of a liquid.
A SLID wafer bond may be able to withstand higher temperatures than a soldered wafer bond. However, a SLID wafer bond may include voids, and accordingly may not provide a hermetic seal.